1. Field of the Invention
The present invention is in the field of retaining or securing objects and, more specifically, in the field of tie-down strapping systems for removably attaching objects to overhead vehicle racks.
2. Description of Related Art
The problem of removably attaching objects such as ladders, pipes or tools to vehicles has long been a vexing one. Typically there will be some type of rack to which one fastens the ladder, tools, and construction materials, but the problem is how to removably attach these objects to the rack. The oldest method is probably to tie the objects on with a rope or cord. However, inexpert knots may readily slip, thereby depositing the ladder and materials in the middle of the freeway during rush hour. Furthermore, secure knots may be so difficult to quickly untie that one has to resort to cutting the ropes to remove the objects from the vehicle.
An alternate solution is to use an elastic "bungee" cord to hook the objects to the vehicle's rack. Although such an arrangement allows for quick attachment and quick removal, it is frequently not adequately secure. Bungee cords are unreliable and can be dangerous because if bungee cords are not applied tightly enough, the attached objects may work loose, resulting in yet another freeway incident. Still another solution is to use tie-down straps with some sort of strap fastening system such as a buckle--particularly one with serrated teeth to grip the strap. A strap threaded through the buckle and cinched down tight will generally hold tight, but one still faces the problem of ensuring that the strap is really adequately tight. If the strap becomes slack, the buckle may release, with serious consequences. Even if the buckle does not release, slackness may allow the pipes or other retained objects to simply slip off the rack.
A major improvement in fasteners has been provided by the complementary surface "hook-and-loop" fasteners such as those marketed under the trademark VELCRO..TM. These fasteners work by an interaction between a loop or pile surface and a hook surface which comprises a plurality of tiny hooks capable of snagging the loops of the pile surface. The hook-and-loop interaction holds the two surfaces together and provides a significant resistance to lateral or sliding motions. However, the two surfaces can be separated relatively easily by vertically peeling them apart. At times the biggest problem may not be in fastening these systems, but in finding an end to peel them apart.
The challenge has been how to most advantageously utilize the hook-and-loop fasteners. There have been numerous inventions utilizing hook-and-loop fasteners in conjunction with straps to fasten various articles. There are a large number of different ways that hook-and-loop fasteners can be combined with straps to form strapping systems, and the precise details of the strap construction can have great effects on the success of various systems. The weight of the items to be fastened also has an important influence in that arrangements that are adequate to fasten light objects may be completely unsuitable for heavier objects.
Hook-and-loop strap systems are often produced with a ring or open buckle attached to one end of the strap. This configuration is shown in U.S. Pat. No. 3,426,363 to Girgard where a hook-and-loop strap is shown with a ring attached to one end and a region of hook fabric at the other end of the strap. On the same side of the strap as the hook fabric, loop fabric extends from the ring to the region of hook fabric. This type of strap can be removably attached to an elongate object by encircling the object with the strap, loop fabric side out, inserting the free end of the strap through the ring, and doubling it back so that the hook region adheres to the loop fabric region.
This method of use is demonstrated in U.S. Pat. No. 3,372,438 to Rinecker, U.S. Pat. No. 4,273,130 to Simpson, and U.S. Pat. No. 4,864,698 to Brame. However, this type of device is not very useful for securing heavy objects like ladders to a vehicle rack. U.S. Pat. No. 4,878,274 to Patricy extends this type of hook-and-loop strap system to mounting objects like a hammock or snow skis. This advance is obtained by adding a second ring to the end of the strap. This way, one ring can be used for doubling back the strap, as explained above, while the second ring can be used to mount an object through an S-hook or a similar attachment. However, this invention does not solve the problem of removably attaching ladders or construction material to a vehicle, since an S-hook arrangement may not adequately immobilize such items during vehicle motion.
There have also been attempts to provide a fastening system that remains attached to the fastened item. An example is found in U.S. Pat. No. 4,963,410 to Bryant. This hook-and-loop strap system is intended to aid in the storage of extension cords. The invention comprises a ring onto which is fastened two hook-and-loop straps, a short strap that has loop fabric on a first side and hook fabric on the other, and a long strap that is all loop fabric on a first side and has both a loop and a hook region of fabric on the other side, with the hook region being at the free end of the strap opposite the ring end. This device can be attached to an extension cord by passing the long strap over the cord and through the ring. The short strap is then allowed to contact the long strap, thus locking the strapping system in place on the cord. This results in the long strap dangling from the cord while the cord is in use. When the cord is looped into a bundle for storage, the long strap can then be wrapped about the bundle several times and locked in place by adhering the hook region at the free end of the long strap to the loop surface of the same strap.